We do not present here a detailed discussion of the anomalous dimensions of the \({\cal O}(\lambda ^3)\)  operators defined in (REF ), which is complicated by the fact that these operators contain a zero-momentum Higgs field. Focussing on QCD evolution only, we find that the Wilson coefficients \({\bf C}_{q_L q_R}\)  of the subleading fermionic operators containing quark fields obey an evolution equation analogous to (REF ) with the anomalous dimension [1]}, [2]}
\(\Gamma _{q_L q_R}(\mu )= \frac{4}{3}\,\gamma _\mathrm {cusp}^{(3)} \left( \ln \frac{m_{Z^{\prime }}^2}{\mu ^2} - i\pi \right) - \frac{2\alpha _3}{\pi } \,,\) 
